Closure for protective device



May 8, 1962 c. R. JACOBS CLOSURE FOR PROTECTIVE DEVICE Filed Oct. 13. 1959 INVENTOR Clifford RJacabs ATTORNEY United States Patent fiice 3,033 l 99 Eitented- May- 8, 1 9.62

tightness and which will act as an eflicient air seal without causing undue discomfort.

In the drawing, FIG. 1 is a perspective view of a gas mask embodying this invention; FIG. 2 is a fragmentary vertical section of the lower portion of the mask; FIG. 3 is a perspective view of the tightening means forming an essential part of this invention.

The gas mask shown in FIG. 1 is particularly intended as a head wound mask. That is, it is so designed as to be suitable for use by patients who have suffered head wounds and therefore frequently cannot use the ordi nary type of mask. It is also suitable for use by others, particularly patients who may be unconscious or whose breathing may be somewhat weak. It includes a large head piece 1 which is formed almost entirely of a gasaerosol filter material. The area is preferably made sufficiently great that the exchange of carbon dioxide and oxygen can take place by diffusion without a bulk flow of air through the filter material. The patient therefore does not have to exert any more force in breathing than would normally be the case. The filter material is hinged at several points indicated at 3. It may be mentioned that a hinge runs entirely down the middle of the back of the device. The hinges are formed of a flexible, impermeable material, such as rubber. This permits folding in several directions. The head piece is also provided with transparent windows 5.

The operation of this mask, as concerns the diifusion, is the same as for the protective devices disclosed in application SN 713,273 filed February 4, 1958 by Hormats, Dwaayer and Sovinsky. The gas-aerosol filter material includes filtering fibers and at least about 25% of finely divided activated charcoal. A suitable composition is disclosed in application SN 733,460 filed May 6, 1958 by Brumfield and Shanty now Patent No. 2,910,979 issued November 3, 1959.

The successful operation of a gas mask of this type depends on the provision of a satisfactory seal with the neck of the patient. My invention is particularly directed to this aspect, which will now be described.

Fastened to the lower edge of the head piece is a neck piece indicated generally at 7. The neck piece includes a sealing tube 9 formed of a sheet of very thin, flexible, but impermeable material, most suitably nylon fabric impregnated with butyl rubber.

The fabric is sealed at 11 to the head piece 1. Within the sealing tube is a regulable tension tightening device 13 which is separately shown in FIG. 3. Tensioning device 13 is formed of an elastic strap 15 and a nonelastic strap 17. These two straps are fastened together in contiguous relationship adjacent their ends, at 19, and also at approximately their midpoints at 21. One or more drawstrings 23 are connected to the ends of the straps. Elastic strap 15 is for-med of .a conventional,- elastic. fabric including longitudinal. rubber, strands,

Within sealing tube 9 the, tension means 13: sure rounded-by encasing tube 25. At; the, back of, the neck piece, encasing tube 2,5.and. the straps. 15, 17, are secured tosealing tube 9... Atthe front of. themask, the. sealing tubev 9. is provided with. an openingwhich, is preferably surrounded by. a metallic; grommet 27. The encasing tube. 25. is provided with-a matching opening for groin? met 27 andissewed-to the outer wall. of tube; 9 abounthe peripheryv of this opening. The. drawstrings; 23* extend outithrough grommet 2.7. andare preferably. proyidedjwith a slidable clasp 29. I

An outer cape member 31 is also secured to the lower portion of head piece 1. It is provided with an elastic insert 33 and is joined at its lower margin to shoulder straps 35. The front of cape 31 carries snap fasteners 37. The shoulder straps 35 are passed under the arm pits of the wearer and are secured at their ends to snap fasteners 37.

When the mask has been put in place and shoulder straps 35 fastened, the neck piece 7 is tightened about the neck by pulling on drawstrings 23. When this is done, the encasing tube 25 as well as the sealing tube 9 are contracted and wrinkled about the neck. The multiple layers of impermeable flexible material form a pad-like seal about the neck. The form of the tension member 13 makes it possible to provide a regulable tensioning. As the tension is increased the elastic strap 15 is stretched, the amount of lengthening being proportional to the tension. The non-elastic strap 17 limits the amount of stretch, since it is selected of such a length that it is longer than the relaxed length of elastic strap 15 but shorter than the elastic strap at its maximum elongation. When, therefore, the drawstrings have been tightened to just the point at which no further stretch of the elastic strap is possible, there will be a known amount of tension applied. The operator will, in the embodiment shown, adjust the tension to a point at which he can detect a small amount of residual possible elongation. This is readily determined by putting the finger under the sealing tube and determining whether there is elasticity remannng.

By the above arrangement a secure but comfortable seal can be obtained.

The adjustable tensioning device can also be used in other environments. One closely analogous to the above is in the gas mask hood shown in Patent No. 2,821,192 granted Jan. 28, 1958 to Randolph Monro. While in the two situations mentioned thus far the tensioning means would normally be used to determine the maximum tension to be applied, it might be used in other cases to determine the minimum tension. In such a case the drawstrings would be tightened until there was no more available elasticity in the member 13. This might be the case with protective clothing where the seal is about a part of the body other than the neck. For example, Italian Patent No. 371,076 shows an impermeable protective suit having seals at the wrists, ankles and waist. My tensioning device would be very suitable for use in these locations.

I am aware that straps have been previously made which are formed of non-elastic material with elastic inserts. In such a device the limiting of the elongation occurs only when the elastic inserts are stretched to the limit of their elasticity. Continuous or frequent stretching of rubber, which is the elastic constituent, to its elastic limit causes it to lose its elasticity very rapidly. Moreover, it is difficult to determine just how near a strap of this type is to its maximum elongation. Such straps are, therefore, not desirable for my purposes. My arrangement overcomes both of these disadvantages.

While I have described one embodiment of my invention in detail, it will be apparent that other changes are possible. I therefore intend the invention to be limited solely by the scope of the appended claim.

I claim:

A gas mask comprising a head piece formed to enclose the entire head of the wearer, said head piece comprising a set of gas-aerosol filter material having an area sufficiently great to permit the exchange of oxygen and carbon dioxide during respiration to take place substantially entirely by diffusion, a neck piece connected to the lower edge of said head piece, said neck piece comprising a sealing tube sealed to said filter material and formed of a thin, flexible, impermeable material, a regulable tension tightening device for said sealing tube comprising an elastic strap and a non-elastic strap located within said sealing tube and joined together at their ends and at least one point intermediate their ends in contiguous relationship, the length of said non-elastic strap being greater than the relaxed length of said elastic strap but less than the length of said elastic strap at its maximum elongation, at least one drawstring fastened to the ends of said straps and extending through the wall of said sealing tube, and means for securing said length in place.

References Cited in the file of this patent UNITED STATES PATENTS 1,046,493 Ring Dec. 10, 1912 1,570,937 Brand Jan. 26, 1926 2,775,967 Sovinsky Jan. 1, 1957 2,800,901 Monro July 30, 1957 

